In all likelihood, the wearer will never set or even try to read the time on her Cartier Tutti Frutti Secret Watch (price available upon request), part of the brand’s 16-piece Mille et Une Heures collection. True to the secret-watch genre—which first became fashionable around the turn of the last century and has enjoyed renewed popularity in recent years—the actual timepiece is hidden beneath a jeweled construction. In this case, the focal point is a single precious stone: an elaborately carved ruby. Like the rest of the bracelet, the ruby evokes the Indian influence that shaped many of Cartier’s high-jewelry pieces during the Art Deco period. Those designs, dubbed Tutti Frutti, mixed diamonds with emeralds, rubies, and sapphires carved into the forms of flowers and leaves. With this timepiece, Cartier splendidly replicates the historic motif and includes the geometric shapes that defined the era. (800.227.8437, www.cartier.com)